Free radical polymerization Flory-Schulz distribution

Free-radical polymerization with chain breaking exclusively by disproportionation or chain transfer yielding unreactive radicals produces a Schulz-Flory mole-fraction distribution. 

The MMD expected for condensation polymerization (and also for free-radical polymerization with termination by disproportionation ) is the most probable (also referred to as Flory-Schulz) MM distribution ... 

The initiator free radicals are not all produced at the same time in free radical polymerization. Consequently, the polymer chains do not all grow at the same time. In addition, a given polymer free radical can terminate another polymer free radical of any desired size, which leads to a random chain length distribution. The derivation given in Appendix A. 20 of this chapter gives what is called a Schulz-Flory distribution of chain lengths. The distribution obtained for termination by disproportionation is identical to the normal distribution occurring in equilibrium polycondensations chains are formed randomly in both cases. 

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